The purpose of this proposal is to cultivate the scientific and professional development of Dr. Julie Bastarache so that she may become an independent investigator. She is currently developing her research career in the Center for Lung Research at Vanderbilt University Medical Center. Under the guidance of Drs. Lorraine Ware and Timothy Blackwell, Dr. Bastarache will design and perform experiments that will enhance her knowledge and research skills in the pathobiology of acute lung injury and acute respiratory distress syndrome (ALI/ARDS). Through laboratory experience, formal coursework, and the peer review process she will gain expertise in experimental design and execution, laboratory techniques, data analysis, and manuscript preparation. These skills will provide the foundation for Dr. Bastarache to pursue an independent career in lung research. Despite progress in understanding the basic pathogenic mechanisms of ALI/ARDS, fundamental questions remain unanswered and disease specific treatments are lacking. Experimental studies have established that intra-alveolar thrombin formation and fibrin deposition as a consequence of a pro-coagulant intra-alveolar environment are detrimental however, the specific mechanisms that regulate fibrin deposition in the airspaces and link lung inflammation and coagulation are unknown. Our preliminary data identifies the alveolar epithelium as a potential source of tissue factor (TF), the major pro-coagulant stimulus in the alveolar compartment. As a result we have formed the following hypothesis: Local production of tissue factor in the airspace in response to pro-inflammatory stimuli perpetuates inflammation and leads to lung injury. Inhibition of TF in the lungs will reduce fibrin formation, decrease cytokine production and limit lung injury. To test this hypothesis we will:1) determine the factors that regulate TF activity, thrombin formation, and fibrin deposition in the acutely injured lung. 2) define the impact of attenuating intra-alveolar TF activity on ongoing inflammation and injury in the acutely injured lung. 3) determine the mechanisms of TF upregulation and activation in the alveolar epithelium. Completion of these studies will provide critical information about the pathogenesis of ARDS that could lead to novel therapeutic strategies.